Since I updated to os X 10.8.4 Safari is very slow and crashes

Hi - I've just bought two brand new MacBook Air 11's. One is 1.3/4/128 and the other is 1.7/8/512. They have both had the same software update and one works fine but the higher spec one does not. This is a Safari software and hardware combination issue I think... When loading any web page in Safari, the console says:

WebProcess[258]: objc[258]: Object 0x7fa25041c9e0 of class NSUserDefaults autoreleased with no pool in place - just leaking - break on objc_autoreleaseNoPool() to debug

... and Safari process runs at 100% CPU until I force quit. Same web page and same router on the other MBA and everything is fine - so this to me rules out a Safari-only issue because it's the same version number.

I'll be returning my MBA back to the Apple store again and will keep doing so until I get another good one.

Come on Apple!

This is my first time on this site but I did want to give you folks some feedback in regards to a slow running OS X 10.8.4. About one month ago I upgraded to my current system. I did so only so that my wife and I could have the convenience of using iCloud. I recently purchased an iPhone 5 and well that's a long story, but it does have relivence. Nonetheless, after about two week my system started getting slower and slower with each passing day. YouTube vidoes were taking upwards of several minutes to load and my system seemed to freeze whenever I tried to go from one page to another.

Initially, I attempted to "RESET SAFARI" AS dominic23 suggested but to no avail. Thanks to dominic23 as I now know how to reset Safari. Then I started looking at after market products like detox my Mac and Clean My Mac 2 in the hopes that these products might fix what was ailing my iMac.

Well long stroy short I went back to this page and read what HR suggested: Reboot modem and router. And like magic my system is running like a champ.

I don't know if this will help, but It worked for me. Thanks and God Bless one and all who read this. BeemerMan 🙂

CGContextClipToRect: invalid context 0x0

This means you are closing a window. A window with a size of 0x0 pixels, is, well not a window. Hence invalid context. Harmless log message though.

Disable any extensions. This is a tiny memory leak and its common log message with many extensions. Disable extensions, this will go away.

Thanks for suggesting I clear the cache, it has significantly improved the browser performance, it still does seem a bit more sluggish then it use too.

since i updatet to 10.8.4 my MacBook Pro is running slower and my Safari simply won't open. I have tried to run disk utility to repair the disk (according to suggestions) but once i get there my trackpad doesn't work and using "tab" I can't seem to reach the "repair disk"... Please I AM GOING CRAZY TRYING TO FIX THIS!!!!!!!!!!

Hello!

I had a real annoying problem with opening some sites, like youtube etc

The problem was in Turn Off Light extension.

After deleting it everything is ok!

Maybe it will help you too.

Emptying the cache worked without having to do all that other stuff. Thanks.

Performing a clean install via USB stick was what I ended up doing by the way - I suspect the machine was poorly imaged. Not had a problem since and it's proving to be an amazing laptop.